The present invention relates to a composite component used for a variety of electronic devices and communication equipment. The invention also relates to a method of manufacturing the composite component.
A variety of composite components including coils, capacitors, resistors, and like components are used widely for various electronic devices and communication equipment. Recently demand for miniaturized and thin composite components has risen. Additionally noise reduction functions of composite components have become more important for electronic devices which operate at higher frequencies and are digital.
There have been L/C composite components constructed by stacking a laminated coil and a laminated ceramic capacitor, such as those disclosed in Japanese Patent Examined Publications, Nos. S59-24534, and S62-28891, which are some examples of small size composite components of the prior art which have a noise reduction function. Furthermore, a variety of structures for L/C composite components have been disclosed in Japanese Patent Examined Publication, No. S62-28891, Japanese Patent Laid-open Publication, No. H01-192107, and so on, each teaching a variation in a three-dimensional arrangement of a coil and a capacitor.
Generally a composite component for noise reduction contains a filter circuit of L-type, T-type, xcfx80-type, or the like, comprising a combination of a plurality of coils and a plurality of capacitors. However, structures of laminated L/C composite components of the prior art have been such that they are capable of composing a filter circuit of only one type of the above circuits. A L/C composite component disclosed in Japanese Patent Examined Publication, No. S62-28891, for instance, has such structure that it can compose only a T-type filter.
Moreover, the conventional composite components had such problems with interference among coils constructed therein, and poor compatibility between coil material and capacitor material in a process of sintering. That is, there are differences in physical properties such as coefficient of thermal expansion, sintering characteristic, and so on, between magnetic material used for increasing a characteristic of the coils and the dielectric material constituting the capacitors. As a result, a defect such as a delamination, warpage, and the like often occurred during sintering process of the laminated composite components.
Since a priority has usually been placed for ensuring the compatibility between magnetic material and dielectric material in order to avoid the above-referred defects, neither material has been able to function effectively to the maximum extent of their properties. Also, there has been a limit in miniaturizing the conventional L/C composite components, since they are composed of laminated coils and laminated ceramic capacitors by stacking them one against another.
On the other hand, an L/C composite component of another type of structure has been suggested, in which a coated copper wire is wound around a laminated chip capacitor. However, this structure has a problem that it reduces yields in production of composite components, since it results in a large dispersion in characteristics of coils. Moreover, this structure has a difficulty in making connections between ends of the copper wire of the coil and terminals of the laminated chip capacitor, thereby making it difficult to miniaturize the L/C composite component or to form the L/C composite component into a chip component.
An object of the present invention is to provide a composite component having a new structure, which eliminates the above-described drawbacks of the conventional composite components, and a method of manufacturing the composite component.
Another object of the invention is to provide a composite component having a structure, which is so designed that the composite component containing various kinds of filter circuits can be manufactured easily and effectively with increased productivity and without making a substantial change in the manufacturing condition, and a method of manufacturing the composite component.
A composite component of the present invention comprises
(1) a capacitor composed of at least one insulation layer and at least two electrode layers; and
(2) a spiral strip of conductor and a plurality of terminals formed in close contact to an external peripheral surface of the capacitor or an external peripheral surface of a portion of the insulation layer not serving for the capacitor, wherein the electrode layers and the spiral strip of conductor are electrically connected to the plurality of terminals.
Another composite component of the present invention comprises
(1) a spiral strip of conductor formed in close contact to an insulation body or a magnetic body, and
(2) a capacitor composed of at least one insulation layer and at least two electrode layers, wherein the spiral strip of conductor and the capacitor are laminated one against another via an insulation layer placed between them; a spiral axis of the spiral strip of conductor is parallel with a plane of the electrode layer composing the capacitor; and, the electrode layers and the spiral strip of conductor are electrically connected.
A method of the present invention for manufacturing a composite component comprises:
(1) forming a capacitor comprising at least one insulation layer and at least two electrode layers;
(2) forming an additional insulation layer on an external peripheral surface of the insulation layer and the capacitor; and,
(3) forming a spiral strip of conductor and a terminal on an external periphery of the capacitor covered by the additional insulation layer.
Another method of the present invention for manufacturing a composite component comprises:
(1) forming a capacitor comprising at least one insulation layer and at least two electrode layers provided on a portion of the insulation layer;
(2) forming an additional insulation layer on an external peripheral surface of the insulation layer and the capacitor; and,
(3) forming a spiral strip of conductor and a terminal on an external periphery of the additional insulation layer.
Still another method of the present invention for manufacturing a composite component comprises:
(1) forming a capacitor comprising at least one insulation layer and at least two electrode layers;
(2) forming a spiral strip of conductor in close contact to an external periphery of an insulation body or a magnetic body; and,
(3) laminating the capacitor and the insulation body or the magnetic body, on which the spiral strip of conductor is closely formed, via another insulation layer placed between them.